Good evening everyone,
Before answering this question, we must create an objective definition of what an 'alien' entails.
So, an alien should refer to any extraterrestrial life forms, in my opinion. After establishing this definition, we can successfully debate the existence of aliens.
Due to the stereotypical perception of aliens as being green with large eyes, I would argue I am a bit skeptical if these type of 'aliens' exist.
However, if one were to focus solely on aliens as an extraterrestrial lifeform, yes, I would argue I do believe in aliens.
It would be absurd to argue that extraterrestrial life does not exist as we are such a small part of the universe that surely, life must exist elsewhere.
I understand why in the past, religions such as Christianity preached humans are at the centre of creation and after studying Philosophical arguments such as the Design Argument and the Anthropic Principle (which argues the universe was created to support human life) people may come to the conclusion Earth is the only place where life exists.
However, due to several technological advancements, we can gain a deeper understanding of the universe. Through studying astronomy and the cosmos, one must believe other lifeforms exist. If not, we are extremely lucky that Earth is the only planet which supports human life.
I hope you find my answer to this question helpful.
Kind Regards,
BigShaq6969.